USPTO Patents Application 10575255

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WHAT IS CLAIMED IS:

1 . A control unit for an electric power steering apparatus
for applying a steering assist force by a motor to a steering
system of a vehicle, the control unit comprising:

a plurality of position detecting sensors for detecting
a rotation position of the motor and outputting it as binary
outputs;

a state function calculating means which calculates a
output value of a state function for every predetermined time
by inputting outputs of the plurality of position detecting
sensors to the state function; and

a judging means to be input the output values of the state
function which respectively continued through the predetermined
time, so as to judge a rotating direction of the motor and
abnormality of rotating direction detection of the motor at one
time.

2 . The control unit for an electric power steering
apparatus according to claim 1 , wherein the state function is
a function the output value of which is in a one-to-one
relationship with the rotation position of the motor without
redundancy .

3. The control unit for an electric power steering
apparatus according to claim 1 or 2 , wherein the judging means
is formed of storage means and judgment table_j^ and the judgment
table outputs a judgment result, i.e., a clockwise rotation,
a counterclockwise rotation, a stop, or the abnormality of the

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rotating direction detection of the motor.

4 . The control unit for an electric power steering
apparatus according to claim 1 or 2 further comprising relative
steering angle calculating means for converting each of the
clockwise rotation, the counterclockwise rotation, and the stop
obtained from the rotating direction into a numerical value and

integrating the numerical value ev e j . y p j, ede Ler ml n^^— t ime^ o

calculate a steering wheel relative steering angle or a column
relative steering angle.

5. The control unit for an electric power steering
apparatus according to claim 4 further comprising steering
velocity calculating means for calculating a steering wheel
steering velocity or a column steering velocity by using the
steering wheel relative steering angle or the column relative
steering angle and the predetermined time.

6 . The control unit for an electric power steering
apparatus according to any one of claims 1 to 5 , wherein the
position detecting sensors are the Hall sensors .

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